Cable clamp



April 22, 1947. TARNQW 2,419,426

CABLE CLAMP Filed Sept. 26, 1946 Patented Apr. 22, 1947 UNITED STATES PATENT OFFICE CABLE CLAMP Nathan Tarnow, Detroit, Mich.

Application September 26, 1946, Serial No. 699,485

1 Claim.

This application relates to cable clamps and more particularly for clamping cables to surfaces having holes through which the cables pass. Such clamps are useful for clamping electrical conductors to junction boxes through knockout holes of which the conductors enter the boxes.

The cable clamp herein disclosed is characterized by its extreme simplicity and economy of manufacture and by the ease with which it is used by the installing electrician.

For an understanding of the clamp herein dis closed, reference should be had to the accompanying drawing.

In this drawing,

Fig. 1 is a front view of the clamp per se.

Fig. 2 is a View as if looking downwardly from Fig. 1, showing the top half of the clamp only.

Fig. 3 is a View as if looking from the left of Fi 2.

Fig. 4 is a back view of the clamp.

In the foregoing drawing, there is shown diagrammatically at I!) a surface having a hole ll through which may be passed a cable I2. The surface may be the wall of a conventional junction box and the hole ll may be a conventional knock-out hole and the cable 12 may be a conventional multiple conductor cable which is to be clamped to the surface Hl as it passes through the hole II.

The clamp consists of two similar complementary halves -4! with each half being in the form of an angularly bent sheet metal piece, including a base portion 22 and a back portion 23. The base portions have their centers curved to fit closely around a cable and also have wings 24 on their ends.

Screws 25 pass through clear slotted holes of the wings 24 of the upper half of the clamp and thread through tapped holes in the Wings 25 of the lower half of the clamp for adjustably connecting the adjacent wings of the complementary halves to clamp them together around a cable.

It will be observed that the back portions 23 are spaced from the wings 24, as best shown in Fig. 2, to permit the surface In to be disposed in front of the back portions 23 and in back of the wings 24, when the clamp is disposed in the hole ll of the surface HI and clamped to a cable l2.

It will also be observed that the back portions 23 are not exactly at right angles with respect to the base portion 22, but rather that the angles between these portions are a few degrees short of as best shown in Fig. 3, whereby adjustment of the connecting means 25 moves the back portions towards the surface to for tight and frictional engagement between the back portions 23 and the surface ii), rocking the halves so that the extremities of back portion 23 first engage the back of surface Hi.

It will also be observed that the back portions are so proportioned with respect to the hole II that they can be entered through said hole from the front of the surface even when the halves of the clamp are loosely connected by the screws 25, provided. however. that the cable 22 is not within the clamp.

Now having described the clamp herein disclosed. reference should be had to the claim which follows.

I claim:

In a cable clamp for clamping a cable to a surface having a through which the cable passes, said cable clamp consisting of two similar complements halves. each half being in the form of an angularly bent sheet metal piece. including a bare portion and a back portion each base portion having its center port curved to fit closely around a cable, and having apcrtured wings on its ends, the back portions being spaced axially from said wings suificiently to permit said surface to be disposed in front of said back portions and in back of said wings, and two screw bolts connecting the pairs of adjacent wings of the complementary halves to clamp them together around a cable, with the base portions in front of said surface and with the back portions in back of said surface, the back portions being so proport oned with respect to said hole that they can be ei'itered through said hole. without the cable in the clamp, from the front of said surface. even when the halves of the clamp are interconnected by the bolts, the improvement which consists in making. the angle between the base portion and the ack portion of each half being slightly less than 90, wheleby tightening of the bolts when the halves are around a cable rocks the halves so that their extremities first engage the back of said surface and the halves are held tightly against said surface.

NATHAN TARNOVV. 

